Archive for November 3rd, 2009

From:
Keep Asking Blog

How does a door closer work?

November 3rd, 2009 by Marshall Brain
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You Asked:

How does a door closer work? — Sonny, Ventnor City, N.J.

Marshall Brain Answers:

There are two kinds of door closers you will typically see in the wild. The first looks like this and is typically used on screen doors and storm doors:

Inside the cylinder is a spring. If the spring was the only thing inside the cylinder you would get a door that slams shut and is annoying. So there is also an air cylinder. When you open the door, the cylinder fills with air. When the door is closing, the spring pushes a piston, which forces the air out of the cylinder through a small hole (which is adjustable to control the closing rate). The leaking air creates the hissing noise that you normally hear with these door closers. There is a nice cut-away view about halfway down on this page.

The second type of door closer is hydraulic and looks something like this:

It works on the same principle, using a spring to provide the closing force. But instead of air to slow the spring down, these closers use a lightweight oil in a configuration that is a lot like a shock absorber. You can see a typical arrangement in this patent. See also this page for repair and adjustment tips for hydraulic door closers.

If you want something simpler so you can DIY, you can always try this approach:

From:
ScienceStuff Blog

Malaria Be Gone! New Vaccine Shows Promise

November 3rd, 2009 by Allison Loudermilk
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Depending on where you live, you may not think too much about malaria. And that’s a ridiculous luxury, considering that every 30 seconds a child dies from the infectious disease, according to the World Health Organization. Despite favored interventions such as using bed nets treated with insecticides, spraying the inside of dwellings, getting rid of standing water and, of course, drug treatments, about 250 million people get sick and 1 million people die every year from malaria, reports the WHO.

Given those numbers, it’s hard not to be interested when a malaria vaccine apparently shows promise — even if it is years away from reaching the people who need it. The candidate in question is RTS,S, a vaccine developed by the pharmaceutical company GlaxoSmithKline Biologicals, working with the PATH Malaria Vaccine Initiative, an organization funded by the Bill and Melinda Gates Foundation. (You know, the same foundation that gives money to people for things like figuring out how to detect tuberculosis with an electronic nose.)

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From:
ScienceStuff Blog

Inhibit Hormones, Eat Soft-shell Crabs Year Round

November 3rd, 2009 by Robert Lamb
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Love soft-shell crab sandwiches? Wish you could have them all year? Well, a team of University of Alabama scientists may just have a way to make that happen.

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From:
High Speed Stuff Blog

Road Car vs. Rally Car vs. Formula One Car

November 3rd, 2009 by Scott C. Benjamin
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Are you ready for a real eye-opener? The short video clip that I want to share with you today provides a clear picture of just how fast a rally car is in comparison to a typical road car and how fast a Formula One car is when raced against both.

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From:
TechStuff Blog

TechStuff Live From Studio A

November 3rd, 2009 by Jonathan Strickland
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Hail, fellow travelers! Your dynamic duo is preparing right now to bring you the most relevant and exciting technology news of the week. That’s right! It’s time for another thrilling episode of TechStuff Live. We bring the show to you every Tuesday at 1:00 p.m. Eastern time and you can watch it right here. Click for the video!

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From:
BrainStuff Blog

Public Service Announcement – If you donate a kidney, you may have to pay… a lot

November 3rd, 2009 by Marshall Brain
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So, you have made one of our world’s most personal sacrifices to give the gift of life to a fellow human being – you have donated one of your kidneys. One would expect gratitude, praise, maybe a medal. But in addition there is something unsettling that may come to visit – huge health care bills. The problem: in today’s health care landscape, your donation turns your missing kidney into a pre-existing condition:

Organ donors hit with shocking bills

Philip Knisely, 53, of Austin, Texas, who donated a kidney to a co-worker a year ago, has received more than $18,000 in related medical bills, and said he was not informed that if he ever lost his employment-related insurance, insurers might consider his having a single kidney an uninsurable pre-existing condition, the American-Stateman reported Sunday.

Some people flip it around though. They do not care about the cost. They donate the kidney and go one step further – they fund the donation themselves:

See also:
- How Organ Transplants Work
- How Your Kidneys Work

[[[Jump to previous PSA - pay attention to static electricity at the gas pump or you could die]]]

From:
Stuff You Should Know Blog

Sociology and Psychology to Leg Wrestle for Total Domination of Serial Killing

November 3rd, 2009 by Josh Clark
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There is a massive, albeit subtle to those of us not really paying attention, grab being made by the field of sociology right now. The social science is making a move to wrestle control of the study of murder from its soft science sister field of psychology. I find this intensely interesting. For the last X decades, since psychology has been around really, the field has had complete and unadulterated domain over the crime of murder. When Jack the Ripper was running around Whitechapel, the cops rounded up everyone who even seemed crazy and sent them off to asylums. The tacit implication was that anyone who butchered women must be insane.

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From:
How-to Stuff Blog

How to Keep a Smile on Your Face This Winter

November 3rd, 2009 by Molly Edmonds
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When it comes to office fashion, my guru is the always stylish Candace Keener, editor extraordinaire here at HowStuffWorks. According to Candace, the fashion trends we should avoid at all costs this season include shapeless tunics, acid-wash denim and anything with Ed Hardy’s name on it (sorry, Jon Gosselin). Her fashion do’s include animal prints and booties (the shoes, not the shorts). While I’ll never match her ability to throw an outfit together effortlessly, I do pay attention to what Candace says about clothing, which was why I was intrigued when she sent me an article about the Happiness Hat this morning.

The Happiness Hat is a white knit cap designed by Lauren McCarthy. That sounds practical enough – winter is approaching, and we all need a good head cover for those cold days. But the Happiness Hat sets itself apart from other cold weather accessories by including a smile sensor.

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From:
BrainStuff Blog

How the smart grid works

November 3rd, 2009 by Marshall Brain
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Electricity is as important as oxygen to a modern society. You can feel that importance as soon as there is a blackout. Our TVs, computers, gaming consoles, refrigerators, microwave ovens, reading lamps and traffic lights all depend on electricity, and without it our world grinds to a halt.

The electric power grid used in the United States to deliver all that electricity has not changed much in more than a century. And because of that, the grid has a number of problems in our modern world. Blackouts and brownouts are one obvious side effect. The old grid is also making it difficult to bring on new sources of energy from renewable sources like wind and solar. And it is making it difficult to create new billing models that would, potentially, save consumers money.

For example, it is expensive for a power company to provide power during peak demand. On the afternoon of a sweltering summer day when everyone has their air conditioners running full blast, power plants and the grid are working at the limits of their capacity. But then at 3AM all of that infrastructure is largely idle. If there were a way, through pricing, to even out the load, electricity would be cheaper and cleaner.

The smart grid promises to solve many of these problems. It should make blackouts less common by making the grid more reliable. It should make it easier for new renewable power plants and home power generation to come on line. And it should help consumers manage their power consumption to lower their peak demand and therefore their bills. Right now the federal government is adding billions of stimulus dollars to the smart grid effort in order to turn the theory into reality.

Let’s start by looking at the power grid we use today. It is designed around the idea of a one-way local model, where a few large power plants provide electricity to a city or region. A power plant pumps its electricity onto transmission lines. These lines carry the power to substations. From these substations the power is distributed to homes and businesses.

In this model, if a transmission line goes down, the whole region may experience a blackout. If a neighborhood loses power, there is no way for the power company to know unless people call and complain. There is no concept of time, so electricity costs the same whenever you use it. There is no designed way for homes and businesses to generate power and put it back into the grid. And there are problems bringing power in from other regions – for example, it is hard for a city in California to take advantage of inexpensive wind power generated in South Dakota.

With the smart grid, two things will change. First, the grid will be designed with a national model in mind rather than a regional model. Second, every part of the system will gain intelligence and bi-directionality. That intelligence will extend all the way down to the individual appliances in your home. For example, your electric car will be able to know how much electricity costs during the day, and may only recharge itself when power is the cheapest. It would also be theoretically possible for your electric car to act like a tiny power plant during peak hours. For example, say you go on vacation and leave your car sitting in the garage. Your electric car (because it has such a large battery), could buy power at 3AM for a nickle per kilowatt hour. It could them discharge itself onto the grid during peak hours when the power company is buying power for 30 cents per kilowatt hour. You could make $10 a day from a transaction like that, and the overall cost of electricity for everyone would go down.

In the same way, major appliances in your home like your refrigerator or dryer would know when power is expensive and inexpensive and tell you about it so you could save money. Your air conditioner could decide to turn itself off in the afternoon when power is too expensive. And if your subdivision or or even your individual home became disconnected from the grid, the smart grid would know it immediately. Blackouts would become less frequent, and should be much shorter.

The Department of Energy offers this amazing statistic: “If the grid were just 5% more efficient, the energy savings would equate to permanently eliminating the fuel and greenhouse gas emissions from 53 million cars.” The smart grid should help provide that efficiency boost.

The big question right now is the cost of all of this new technology. The hope is that a push by the federal government, combined with national thinking for transmission lines, can help kick start the process. With luck, we will all be taking advantage of the smart grid within a decade or so.

See also (the first 3 minutes is a skippable intro):

DOE smart grid book

From:
The Coolest Stuff on the Planet Blog

Lemur Fortress — What’s not to love?

November 3rd, 2009 by Amanda Arnold
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The last time I flew over Manhattan, I looked out the airplane window down at the island of skyscrapers and thought, “Ouch. That would really hurt if you stepped on it.”

But that was before I became acquainted with the forest of knives they’ve got over in Madagascar.

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